The present invention relates to digital imaging, and in particular, to systems, methods, and devices for testing, measuring, and characterizing illumination light sources and lighting systems used in the capture of test and calibration images for testing, calibration, characterization, and qualification of imaging devices, such digital cameras and digital imagers.
Unless otherwise indicated herein, the approaches described in this section are not admitted to be prior art by inclusion in this section.
Digital imaging is highly complex and involves many individual components and systems and their interactions with one another to produce a digital image. To produce a digital image of a given quality, a system integrator or system designer must account for the behavior, characteristics, and capabilities of each component in the system. From the lens and imager chip to the imager control circuits and backend image processing software, each component of a digital imaging system contributes various behaviors and nuances that affect the final digital image.
To determine the quality of the final images produced by a given digital imaging system, testers and engineers can use any number of standardized and proprietary tests to evaluate color sensitivity and reproduction, vertical and horizontal response uniformity, image noise, and other image characteristics. Many of such tests involve capturing images using a complete or nearly complete imaging system with various settings under various lighting conditions. To isolate various capabilities of a specific imaging system during testing, it is necessary to eliminate variations in the lighting systems used to characterize, test, and calibrate the imaging system.
Lighting systems can vary greatly. For instance, not only can lighting systems vary from one lighting system to another, but a particular lighting system can vary over time due to the change in color and light output as the lamps, or other light sources, warm up and cool down. Additionally, as lighting systems age, the color and illumination quality of various bulbs and lamps can change, so it is necessary to test, measure, and recalibrate lighting systems on a regular basis.
Traditional illumination testing techniques include various arduous manual processes that are labor and time intensive. Use of such manual processes and systems can cause significant delays in the testing, calibration, and production of digital imaging systems and quite often require highly trained engineers or technicians to ensure the process is performed accurately.